Mark on new galaxy rasbora

[CapS]

Hey, thanks for the tips.
I also thought it was fungal and used pimafix, but this didn't seem to help and sadly the one in the photo died after I isolated it.
I also had one which was showing signs of infection a few weeks ago and had a good look around the tank (moved everything) and I am pretty sure that one also died as I can't find any signs of it anywhere - no ammonia spikes so fingers crossed it didn't impact on the tank too much.
I ended up doing 1 week of Melafix, 1 week of Pimafix, and after removing the ill one, another week of Pimafix to be safe (added some bubbles to help with oxigenation which I read was an issue when they are used) and I am happy to say none of the other remaining 4 are showing any signs of illness yet so hoping that helped.
Total hardness is between 6.5 to 8.6 Gh (120-150mg/L), and Carbonate is 4 Kh (7-mg/l) but PH is pretty stable at 7.2-7.6 so seems alright from what I read. I've added the conversion in case I got one of the other values wrong and someone spots something off.
I actually really enjoy the danios and would consider getting more to replace the ones I lost, but I am not sure if there is something wrong with the tank or with the supply as mentioned by DoubleDutch. Guppies and blue shrimp seem pretty happy otherwise.

[DoubleDutch]

There isn't anything wrong with the fish or the supply but I am starting to suspect CPD's have sonething like Dwarf Gouramis. A species specific issue. At several forums around the world the same issues seem to occure.